1. Field of the Invention
The present invention relates to industrial automation systems and, more particularly, to a modular control device of an industrial automation system and method for configuring the modular control device of the industrial automation system.
2. Description of the Related Art
Industrial automation systems serve to monitor and perform open-loop and closed-loop control of technical processes, in particular in the field of the automation of fabrication, of processes and of buildings, and permit control apparatuses, sensors, machines and industrial systems to operate in a way which is to be as autonomous and independent of human intervention as possible. Owing to the continuously increasing significance of information technology for automation systems that comprise numerous networked control units or computer units, methods for reliably making available functions that are distributed via an automation system are becoming ever more significant with respect to making monitoring functions and open-loop and closed-loop control functions available.
Interruptions of communication connections between computer units of an industrial automation system or automation devices can give rise to undesired or unnecessary repetition of a transmission of a service request. This gives rise to additional utilization of communication connections of the industrial automation system, which can lead to further system failures or faults. Furthermore, messages that are not transmitted or are transmitted incompletely can, for example, prevent an industrial automation system from transitioning to or remaining in a safe operating state. Finally, this can lead to failure of an entire production system, and costly production stoppage. A particular problematic situation in industrial automation systems often results from signaling traffic with messages that are comparatively numerous but relatively short, which exacerbates the above problems.
EP 1 188 293 B1 discloses an interface module for a stored-program controller that permits data requests to be transmitted to the stored-program controller via a communication device or a computer unit outside an industrial automation system, such as by Internet. The interface module comprises a processor with a real-time operating system, a communication network interface and backplane bus driver for a backplane bus system of the stored-program controller. Furthermore, a double protocol stack that comprises a first and second protocol stack, and a client control process, are implemented in the interface module. The client control process serves to communicate with the double protocol stack and the backplane bus driver and to initiate data requests. In addition, a server control process is provided to communicate with the double protocol stack and the backplane bus driver and respond to data requests. Furthermore, a protocol control process serves to communicate with the double protocol stack and the backplane bus driver and to retrieve and reply to requests that are directed to the protocol stack. While the first protocol stack is provided for messages that are uncritical in terms of timing, messages that are critical in terms of timing are handled by the second protocol stack.
US 2004/0114591 A1 describes a stored-program controller that comprises a backplane bus system and modules that are connected to the backplane bus system and that communicate via the backplane bus system via an internet communication protocol (IP). Each module has a separate IP address.
EP 2913727 A1 relates to a modular industrial automation device with a backplane bus system and a plurality of function modules that are connected to the backplane bus system and that each comprise a communication network adaptor, a function unit for implementing a communication protocol stack and a bridge element that is linked to the communication network adaptor. Furthermore, a router module that is connected to the backplane bus system is provided, which comprises a communication network adaptor, a function unit that is linked to the communication network adaptor and has the purpose of implementing a router communication protocol stack, and in each case a linking element for each function module. Such a linking element links the function unit for implementing the router communication protocol stack to the bridge element of the respective function module via the backplane bus system. Only the communication protocol stack of the router module comprises routing functions.